Safe voltage detection on railway catenary systems
Safe voltage testing on overhead line systems
The BO-A 2.0 is a voltage detector for railroad overhead contact line systems, which is used to determine the absence of voltage in accordance with the five safety rules.
- Unlock
- Secure against restarting
- Determine absence of voltage
- Earthing and short-circuiting
- Cover or cordon off neighboring live parts
Use of the BO-A 2.0
The BO-A 2.0 is used wherever electrical work has to be carried out on the overhead contact line and the overhead contact line supply network in a de-energized state. It is also used during normal operation of the systems when the voltage state on the overhead contact line must be clearly determined on the open line, in the station or in the tunnel.
Typical applications include measuring on the contact wire, suspension cable, mast switches for cross and longitudinal separations as well as on feeder, bypass, booster and feeder lines. Users include railroad network operators, overhead line and track construction companies as well as companies responsible for track safety, disconnection and earthing of overhead lines at construction sites.
Versions of BO-A 2.0
The devices are available for voltage levels of 15 kV, 11 kV and 25 kV and for frequencies of 16.7 Hz, 50 Hz and 60 Hz. There is also the BO-A DC version for DC voltages in the range from 100 V to 3 kV DC (e.g. for DC overhead lines on streetcars). The voltage detectors are available either as a three-part plug-in system or with a telescopic rod. The total length is 4.7 m for the plug-in system and 5.4 m for the telescopic rod.
In addition to the plug-in system, there is also a version with a universal adapter that allows customers to continue using their existing earthing and operating rods.
Release of operating resources by Deutsche Bahn
Like its predecessor, the BO-A, and the BO-A DC, which serves as a counterpart for DC overhead lines, the BO-A 2.0 also successfully passed the railroad approval of Deutsche Bahn under the approval “3 Ebgw 02.71” on 28.07.2021. This makes Deutsche Bahn a reference customer for other railroad network operators worldwide. In contrast to the BO-A 2.0 devices sold worldwide in accordance with IEC 61243-1, the German market also requires compliance with VDE 0681-6, which is also guaranteed.
The safety features of the BO-A 2.0
The BO-A 2.0 is equipped with a comprehensive self-test device that checks the display elements, the battery and the evaluation electronics each time it is switched on via the button. To further increase safety, the voltage tester can also be cross-checked on a live cable if one is available.
A bright LED display, which is easy to read even from a distance from the telescopic pole, and a clearly audible acoustic signal reliably inform the operator about the voltage status of the overhead line. The BO-A 2.0 recognizes this even if the wrong frequency is used and clearly alerts the user via the acoustic signal.
The BO-A 2.0 is designed in such a way that it reliably detects the voltage status even in borderline situations, when the overhead line is disconnected but not earthed and despite live lines running in parallel. Even when the overhead line is switched off and not earthed, it guarantees reliable voltage monitoring.
If the device is not switched on manually using the switch-on button, but is connected directly to the overhead line, it switches on automatically as soon as voltage is applied to the overhead line. The BO-A 2.0 immediately gives a visual and audible warning of the presence of voltage. Depending on the version, this standby function is activated or deactivated at the factory.
In contrast to the standard version, devices are available with an extended standby time: they do not switch off automatically after 65 seconds as usual, but only after 180 seconds with no voltage applied. This is particularly helpful if additional time is required for earthing and short-circuiting after the voltage-free test.
Mandatory repeat test
The trade association stipulates in DGUV V3 that voltage detectors must undergo a repeat test every six years. During this test, the response thresholds of the device are checked and the long-life lithium cell is replaced, among other things, so that the battery does not need to be changed within the next six years during normal use.
Irrespective of the periodic inspection, a visual inspection for possible damage to the appliance must be carried out before each use. The rating plate should also be used to check whether the appliance is suitable for the voltage and frequency at the place of use.
Safe transportation in the track bed
In addition to the voltage detectors, Horstmann offers a versatile storage bag that can be used both as a carrying bag and as a rucksack. A major advantage of this bag is that you have your hands free when carrying it in the track bed. Its high visibility color and reflective stripes ensure that the mandatory high visibility vest is not concealed. If required, the bag can be extended with an additional carrying bag to conveniently transport an earthing pole and the earthing and short-circuiting set, for example.
Product features at a glance
The product features and benefits for the user can therefore be summarized as follows:
- Low weight – easy handling and transportation
- Complete self-testing – maximum safety
- Simple plug-in and telescopic system – Easy and quick to use
- Bright LEDs and loud acoustic signals – Good perception in all ambient conditions
- Shock-resistant and no battery replacement necessary – Maintenance-free with a long service life
- Automatic frequency detection – warning when used in networks with other frequencies